The present invention relates to a therapy and exercise unit for restricted-guidance knee joint motion, having two lower leg receivers, which are disposed on a guiding arrangement and connected by articulated devices to a transmission element of the guiding arrangement, which transmission element connects the lower leg receivers to one another in a motionally coupled manner such that a swivelling motion of the one lower leg as a result of bending of the knee initiates an oppositely directed swivelling motion of the other lower leg.
From WO 96/29040 a therapy and exercise unit of the type described initially is known, which has as a transmission element a cable, to which are connected the articulated devices which via articulated levers establish a connection with the lower leg receivers. The articulated devices connected in a motionally coupled manner to one another by the cable are guided in a horizontally disposed guiding arrangement, which takes the form of a guide rail and is disposed on the ground or on the subsurface, on which the patient having therapy is situated. Thus, the lower leg receivers in the known therapy and exercise unit are situated during operation above the articulated devices.
During operation of the known therapy and exercise unit, in individual cases it has proved difficult for the patient having therapy to move the extended leg out of the extended position.
The object of the present invention is therefore to propose a therapy and exercise unit of the type described initially, which makes it easier for the patient to move the extended leg out of the extended position in order to continue the motion therapy.
Said object is achieved by a therapy and exercise unit having the features of claim 1, claim 3 or claim 5.
In the solution according to claim 1, for connection of the lower leg receivers to the articulated devices, a lever is provided which produces a restoring moment, which in terms of the direction of rotation counteracts a leg extension, about a pivot of the respective articulated device.
The manner according to the invention in which the lower leg receivers are coupled to the articulated device ensures that, instead of the entire weight of the extended leg acting in a manner which stabilizes the extended position, at least part of the lower leg accommodated in the lower leg receiver causes in relation to the pivot of the articulated device a moment counteracting said stabilizing position. Lifting of the leg, in order at the start of flexion of the leg to move at least slightly out of the extended position, is therefore made far easier for the patient.
When the lever is designed so as to be variable in its effective length, a variation during the movement or alternatively an adaptation to the lever ratios of the legs of the patient may be effected.
According to a further solution according to the invention, the articulated devices are disposed on the guiding arrangement in such a way that the articulated device, which via the relevant lower leg receiver is associated with the flexed leg, is in a higher position than the articulated device, which via the relevant lower leg receiver is associated with the extended leg.
The energy potential of the flexed leg, which is greater than that of the extended leg, may therefore be utilized to enable the patient to move the extended leg out of the extended position.
An advantageous embodiment of said solution according to the invention consists of designing the guiding arrangement in such a way that it comprises an inclined guideway for the articulated devices.
According to a further solution according to the invention, the lower leg receivers are disposed on the articulated devices in such a way that the axis of force of the extended leg is situated below a pivot of the articulated devices.
It is thereby ensured that, during the transfer of the flexed leg from its end position into the extended position, a force is transmitted via the transmission element to the leg situated in the extended position, with the result that a restoring moment, which in terms of its direction of rotation counteracts the extension movement of said leg, arises about the pivot of the articulated device. Said measure also makes it easily possible for the patient to surmount the dead centre of motion in the therapy and exercise unit which arises when a leg is in the extended position.
The previously described, independent solutions to the problem, on which the invention is based, may also be combined in any desired manner with one another in order to enhance even more the effect, already achieved by each individual solution, of noticeably improved surmounting of the dead centre of the motion effected in the therapy and exercise unit.
There now follows a detailed description of preferred embodiments of the independent solutions according to claims 1, 3 and 5.
Thus, in each of the solutions according to the invention, it proves advantageous when the articulated devices are variable in terms of their arrangement relative to the transmission element. It is therefore possible, for example, to vary the range of linear motion along the guideway without having to vary the position of the therapy and exercise unit relative to the patient.
Furthermore, in all of the solutions according to the invention, it proves advantageous when the articulated devices are provided with a swivel radius limiting device so that the radian measure of the desired range of motion may be fixed exactly.
An improvement in the practical handling of the therapy and exercise unit may be achieved in each solution when the lower leg receivers are releasably connected to the articulated devices by a snap-in connection.
It is therefore possible, for example, to effect the positioning of the therapy and exercise unit next to the patient without the projecting lower leg receivers and hence make the positioning more comfortable for the patient.
A particularly advantageous construction of the snap-in connection is achieved when there is provided on the lower leg receivers a connecting pivot pin in the form of a snap-in pin, which is intended for engagement into a swivel eye of the articulated device.